NF-kappaB is a heterodimeric transcription factor comprised of p50 and p65 subunits that activates gene expression by binding to specific sequences of duplex DNA. NF-kappaB is absolutely required for the transcription of human immunodeficiency virus type I (HIV-l) DNA early in viral infection and regulates many key genes induced in inflammation and apoptosis. We are interested in blocking NF-kappaB activity within living cells to inhibit expression of NF-kappaB-dependent genes via a high-affinity RNA "decoy". If vectors encoding such RNAs can be introduced into living cells, these decoy RNAs might titrate levels of functional NF-kappaB protein, leading to reduced expression of NF- kappaB-dependent genes. One long-term goal involves gene therapy to create T cell clones resistant to HIV-1 infection. My proposal has four separate specific aims: l. Can we identify RNAs that bind p50 homodimers [(p50)] with high affinity? 2. How do selected RNA ligands bind to (p50)2? 3. What is the effect of decoy RNAs on in vitro transcription from templates that are activated by NF-kappaB? 4. Can transcription from an NF-kappaB-dependent promoter by inhibited by expressing decoy RNA in cells?